OCZ DDR PC-4200 Dual Channel

"OCZ Performance Series PC-4200 Dual Channel memory using state of the art HyperSpeed? technology is capable of achieving outrageous speeds of up to 533 MHz at CL 3-4-4-8. OCZ PC-4200 Performance Series Dual Channel memory has been designed and fully optimized for use on Intel i865/i875 chipset-based systems." Liquid3D puts this statement to the test.. and then some!

PAT on/off

On the Intel front, it's taken a bit of time to find a chipset to rival the nForce, and while Intel's efforts were originally mired down by Rambus influence, and RDRAM considerations they finally decided to adopt the more widely accepted DDR standard. Intel's 850 chipset was their first dual channel effort, although based on RDRAM it was a plateau in their chipset ascent. Granite Bay was the predecessor of the venerable Canterwood, and was Intel's first synchronous Dual DDR chipset. Albeit significantly slower then it's offspring at 4.2GB/s it was, none-the-less the break from the RDRAM strangle-hold. RDRAM, while an excellent memory solution, was simply too costly and its Patent holders seemed to be involved in one litigation after another. Politics aside Granite Bay, exhibits many of the attributes of Canterwood. Both are 1005-BGA chips, feature the same die size, share the 8x AGP. And except for Gigabit LAN, and PAT, Granite Bay and Canterwood are closely related. But it is PAT which will be our focus, and its ability at latency reduction.

From the screenshot at the previous page running OCZ's PC4200 at CAS-3-4-4-8 / 2.85V, and 285FSB (1:1) Sandra reads a 5924MB/s Buffered Bandwidth result. Now we shall run the system at 280FSB / CAS-3-4-4-8 / 2.85V, and again run with PAT disabled;

While 5975MB/s comes no where near the theoretical bandwidth, it's still decent bandwidth given the latencies, and disabling of Performance Acceleration Technology. Now we'll run the system at 280FSB again (1:1) at CAS-3-4-4-8 / 2.85V, and enable PAT;

As you can clearly see enabling PAT improves bandwidth by 349MB/s, perhaps not by a huge amount, but significant none-the-less. Now just for further comparison, we'll run the system again at approximately 280FSB (277FSB) except change the CAS to 2.5. Ergo the parameters will be as follows; 277FSB / CAS-2.5-4-4-8 / VDIMM 2.85;

Although this may seem prima facie to many, it is none-the-less, empirical evidence of "real-world," or effectual bandwidth with Intel's PAT, and a BIOS reduction of CAS latency. And to show the effects temperature has on the NB, this next screenshot was taken when I'd removed the Maze-4 system to add the Z-chipset block. The Vantec Tornado 92mm/119CFM is currently the most powerful HSF available on the market. When Thermalright designed it's SLK-947-U, and SP-94 to accommodate this fan, you can be sure they knew what they were doing in so far as over-lap is concerned. A great deal of air comes in contact with the surrounding mosfetts and especially the NB. Here-in lays the empirical evidence;

We've now surpassed the theoretical bandwidth of the 875 chipset, and excellent achievement. And 22C is an excellent temp for air-cooling. This is all attributable to the Thermalright SP94, Vantec Tornado 92mm, and AS5.